عنوان مقاله [English]
Evaluation of adaptation and stability of winter oilseed rape mutant lines in cold and mild cold regions of Iran by GGE biplot method
Background and Objectives
Oil seedrape is the third most important oil crop in the world after oil palm and soybean. The world's oil rapeseed production was 4.6 million tons in 2018-2019 and has the ability to compensate for the lack of edible oil in Iran (containing 40-45% oil). The production of this crop is mainly done by using two zeros cultivars with a low level of glucosinolate in the feed and the absence of Erucic acid in the oil. Two types of oil seedrape are cultivated in Iran, spring and autumn. Spring type is cultivated in warm regions of the Caspian Sea coast and southern regions of the country and its autumn type is mostly cultivated in cold and mild cold regions.
Materials and Methods
In this study 16 rapeseed mutant lines obtained through gama radiation of three rapeseed cultivars Talaye, Zarfam and Express with 800, 900 and 1200 gray dose rates , followed by 7 selfing generation, are compared two years for earliness, seed and oil yield and other important agronomic traits in four regions Karaj, Kermanshah, Esfahan and Zarghan with three check varieties.
The oil content of rapeseed varieties and lines will be determined by NMR (nuclear magnetic resonance) at chemic laboratory of Oilseed Crops Research Department of Seed and Plant Improvement Institute. Finally, the highest yield early maturity lines will be defined.`
Each treatment is sown in plot with four rows, four meters lenght and 30 cm between row distances. The experimental field will be prepared in late summer and chemical fertilizer should be given to it. The sowing experiment is planned for late week of September until the first week of October.
At the end of each cropping year, the yield of each plot will be harvested separately and the statistical calculations will be carried out after the gathering of two years results by GGE biplot method.
Results of combined ANOVA showed that main effects of year and genotype, interaction of location ×genotype; year × location, and interaction of year, location and genotype had significant effect on grain yield. The genotypes showed the highest and the lowest grain yield in Kermanshah 4016 kg/ha and Zarghan 2886 kg/ha stations, respectively.
Line T-900-4 produced the highest grain yield 3840 kg/ha in all locations. To study the interaction of genotypes and environments, GGE biplot method was used. Based on the polygonal graphs related to genotypes, line Z-800-6, Z-900-7, Okapi and Z-800-3 produced the highest yield in Karaj, Zarghan, Kermanshah and Esfahan, respectively. Regarding to the imaginary ideal genotype graph and biplot of genotypes and environments and seed yield ranking, line Z-900-7 were identified as the best genotypes due to its higher yield and stability.
Oil crop, grain yield, combined ANOVA , mutant.